Method for waterproofing



Patented Sept. 5, 1933 UNITED STATES PATENT OFFICE No Drawing.Application July 3, 1930 erial No. 465,792

1 Claim.

This invention relates to waterproofing, and particularly to theapplication of a layer of waterproofing or dampproofing material onbuild- 5 ing structures such as walls, partitions and the like.

The object of the invention is to provide a method for applyingwaterproofing material, such as asphalt, tar or the like, effectivelyand expeditiously, so as to give a very tenacious and 30 durable bondbetween the waterproofing material and the surface to which it isapplied.

A further object of the invention is to provide a method whereby thewaterproofing material may be applied in heated condition as a sprayformed, for instance, by air from an air gun or the like projecting thehot material against the surface in divided form and at high velocities.

The waterproofing medium is preferably asphalt but may be tar or otherwaterproofing medium adapted to be applied in liquid form and to hardenor solidify after application to the surface to be waterproof. Theasphalt is of the semi-mastic type out back with asoftening agent,preferably volatilizing on exposure so that the applied asphalt willtend to harden in place.

For many purposes I prefer to mix the waterproofing medium, asbestosfibres or other filler to add to the body of the applied material, the

fibres being of medium length and applied in proportions of lbs. ofasbestos fibre to 50 gallons of asphalt although these proportions maybe widely varied. The asphalt or mixture of asphalt and asbestos or thelike is supplied from a container, air pressure being applied to forcethe material through a pipe or hose to the air gun. The asphalt materialmay be heated in the' tank or in the hose connection or both, the objectbeing to have it in sufliciently heated condition to be effectivelysprayed and applied by the air gun. In practice the material leaving thegun may be around 300 F. for instance, and on contact with the wall ormasonry may be at over 220 F.

This heating liquefies the asphalt and reduces its viscosity to such anextent that it is divided by the air blast of the air gun and projectedin drops at high velocity so as to spatter and spread on the surfacebeing treated and enter the crevices and pores of the surface so as toform a continuous, tightly clinging layer. Preferably the air gun nozzleis positioned within a few feet of the surface to force the materialdirectly on to the surface and into the interstices thereof. Thethickness of the layer may vary, and for instance at the rate ofapplication of 15 to 20 square feet of wall surface per minute a coatingto of an inch may be sufiicient for usual conditions, and a plurality ofsuccessive layers may be applied if desired.

The fluid asphalt in its heated condition also acts as a carrier andlubricant for the asbestos 01' other filler and permits the fibre toleave the nozzle of the spray gun without any clogging The spray gun ispreferably of the type used for heavy liquids, such for instance asemulsions, and it is usual to supply the liquid to this type of gununder pressure. In cold weather and wherever desirable to overcome thecooling effect of the expanding air jet, I may heat the air supply tothe gun sufficiently to avoid any over-chilling of the asphalt. Thisheating as well as the heating of the asphalt may be accomplished in anyconvenient manner, for instance by passing a current through the metallining of a hose, this current being of sufficient amperage to give thedesired heating effect and being controllable so as to control thetemperature of the asphalt and the air as desired. In practice, I havefound a pressure from 30 to 4.0 lbs. on the asphalt container is amplysufiicient, and a similar pressure for the air gun jet so that a singlecompressor can readily be used to supply both the asphalt container andthe air gun.

While I have used the term waterproofing in the specification, I mean tohave it understood in a very general sense of waterproofing,dampproofing or in any wise coating against moisture. The particularspray means is also immaterial providing that it gives the desiredresult of dividing the asphalt material in heated condition andprojecting it against the surface. A centrifugal spraying means might beused as well as the air gun method above described in detail.

By the method of this invention the waterproofing material is applied byprojection against the wall at any desired angle to the surface,preferably substantially normal to the surface; there is no substantialmovement of the asphalt along the surface and each drop and particle ofasphalt tends to cling in the position it strikes the surface. The hotasphalt also penetrates deeply into the masonry joints and brickmasonry, and any porous material against which it is projected, givingnot a mere film but an outer layer of any desired thickness securelyanchored and bound to the supporting surface which is beingwaterproofed. This heating of the waterproofing medium also dispenseswith thinning by any extra solvent, making the final layer in itsoriginally admixture of over forty pounds of asbestos fiber to fiftygallons of the asphalt, heating said mixture and applying pressurethereto so that the hot asphalt acts as a carrier and lubricant for thefiber, and spraying said mixture at high velocity onto the surface to bewaterproofed so that the asphalt and asbestos will form a continuoustightly clinging layer containing over 90% of waterproof material andthe solvent will volatilize and cause the mixture to harden in place asa final completely waterproof coating of asphalt and asbestos.

WALTER H. STORM.

